1. Field of the Invention
This invention relates to a novel fitted sheet for a waterbed and to a novel fixture for holding the novel sheet in place on the waterbed. The invention includes also the combination of the novel sheet and four (4) novel fixtures with a waterbed mattress in a supporting frame.
2. Description of the Prior Art
The most common type of waterbed includes a mattress comprising a water-filled bladder and a substantially-rectangular frame which confines the bottom and sides of the mattress. A liner is usually present between the frame and the mattress to catch any liquid that may leak from the bladder. Sheets and other bedding are positioned over the mattress prior to their use. Because of the resiliency of the waterbed mattress and the movements of the mattress when the bed is in use, the bedding does not remain in place as with stuffed or inner-spring mattresses. Also, because of the considerable weight of the waterbed mattress and substantial pressure of the mattress pressing against the sides of the frame, it is considerably more difficult to tuck the bedding along the sides and under the mattress.
Various attempts have been made to overcome the problems associated with changing the bedding, with making up the beds, and with retaining the bedding in place on a waterbed mattress. U.S. Pat. Nos. 4,089,075 to M. I. May and 4,389,741 to L. D. Larson, each provides fixtures that attach to the inside of the frame, which fixtures clamp the bedding to the frame. While this approach holds the bedding in place, changing the bedding and making up the bed after use is inconvenient. Also, although it is not necessary to lift the waterbed mattress, it is inconvenient to apply the clamps to the bedding, especially in view of the substantial pressure of the mattress against the sides of the frame.
U.S. Pat. No. 44,521,970 to J. M. Jester, provides four (4) anchors under the waterbed mattress that are held by the weight of the mattress. An anchor is attached to each corner of a sheet under the mattress, thereby holding the sheet in place. Lifting the weight of the mattress and pushing against the side pressure of the mattress makes changing the bedding and making up the waterbed difficult and inconvenient.
U.S. Pat. No. 44,301,561 to M. McLeod, provides continuous hook-and-loop fasteners along the margins of the liner on both the inside and outside thereof. A bed pad has its margins fastened along the inside margins of the liner, and a flat bottom sheet has its margins fastened along the outside margins of the liner. A flat top sheet is sewn to the bottom sheet along the margins of the foot portions thereof. This arrangement requires considerable time and effort to fasten and unfasten all of the margins of the bottom sheet to and from the liner against the considerable sideward pressure of the mattress pressing against the side of the frame.
U.S. Pat. No. 44,040,133 to M. B. Gilreath provides four (4) straps that are held by the weight of the mattress and extend upward adjacent to each of the mattress corners. The straps have hook-and-loop fasteners on both sides along the extended margins of the straps. Each of the four corners of a bed pad attach to the inner fasteners of the strap. Each of the four corners of a flat bottom-sheet attach to the outer fasteners. Each of the two corners at the foot of a flat top-sheet attach to the two corners at the foot of the bottom-sheet with hook-and-loop fasteners. This arrangement requires considerable effort to position the straps under the mattress, and also to fasten and unfasten the sheets against the considerable sideward pressure of the mattress against the sides of the frame.